86 MICRO-ORGANISMS IN WATER 



Numerous other investigations of the ice supplied to 

 Berlin are recorded, and in some instances as many as 

 25,000 micro-organisms per CO. were discovered, whilst, 

 ■on the contrary, in artificial ice, for the preparation of 

 which distilled water was used, organisms were almost 

 •completely absent. 



Still more recently Heyroth ^ has published a series 

 of investigations on ice as obtained from various places 

 in the neighbourhood of Berlin, and supplied by different 

 <;ompanies for public consumption. The following table 

 shows the places from which the ice was collected, as 

 well as the number of bacteria contained in 1 c.c. of the 

 ice-water. 



Bacterial Contents of Ice (Heyroth) 



Kumber of bacteria 

 Day of Investigation Origin of the Ice in 1 c.c. 



19. 9.85 Plotzen Lake 490 



5.10.85 „ 4,900 



12.10.85 „ 121 



19. 9.85 Eummelsburger Lake and waters near Kopernick . 425 



5.10.85 „ „ „ . 210 



12.10.85 „ „ „ . 1,150 



12.10.85 Kaiser-bassin at the Navigation Canal, Spandau . 634 



12.10.85 Pond at Eeiuickendorf 2 



15. 5.86 Plotzen Lake 1,835 



17. 5.86 Kiver Spree at Treptow 171 



17. 5.86 „ „ 30 



17. 6.86 „ „ 1,780 



18. 5.86 Peaty pond-water from Lichtenberg Meadow . . 800 



26. 5.86 „ „ 500 



15. 6.86 Flaken Lake at Erkner 448 



15.6.86 Peaty pond-water at Eummelsburg. . . . 392 



15. 6.86 Pond-water at Tempelhof 1,510 



15. 6.86 Peat-meadows at Rixdorf 2,040 



15. 6.86 Lichtenberg Meadow and Lichtenberg Lake . . 2,750 



29. 6.86 Lake Reinickendorf 47 



29. 6.86 Weissen Lake 735 



29. 6.86 Rtimmelsburg Lake and waters near Kopernick . 765 



29. 6.86 Pond-water (situation not specified) . . . 14,400 



^ ' Ueber den Eeinlichkeitszustand des nattirlichen tind kiinstlichen 

 Eises,' Arheiten a. d. haiserlicJien Gesundheitsamtej vol. iv., 1888, p. 1. 



